This proposal describes the continued maintenance and development of BioGPS (http://biogps.org), a gene annotation portal based on the principle of crowdsourcing. Genome-scale science is becoming increasingly common for performing unbiased surveys of gene function. Technologies exist for high-throughput interrogation of genetic variation, gene expression, protein expression, protein modifications, epigenetic variation, and other molecular features. Using these approaches, scientists can rapidly identify a set of candidate genes that are relevant to their biological system of interest. However, understanding current knowledge of those genes remains a significant challenge. There are hundreds if not thousands of online sites with gene annotation information, all having some partially overlapping subset of information relative to the other sites. BioGPS was created to simply navigating the landscape of gene annotation resources. BioGPS does this by promoting two key principles - community extensibility and user customizability. Community extensibility means that we empower any user in the BioGPS user community to add new content to BioGPS. User customizability means that we allow each individual user to tailor BioGPS to their individual needs. Building on these principles, BioGPS has evolved into a highly functional gene portal that is widely used in the genetics and genomics community. This proposal builds on the previous project period's success. As a web application built on crowdsourcing, this proposal focuses on two mechanisms for continuing growth and positively impacting biomedical research. First, we will pursue several strategies for better attracting new users and retaining existing users. These strategies include implementing new features to improve usability, developing focused outreach efforts, and introducing social networking dynamics. The second strategy pursued in this proposal is to add new mechanisms for users to contribute to the BioGPS community. Specifically, we will create a new set of features around analyzing and sharing gene lists to complement our existing emphasis on single genes. BioGPS is a useful tool for biomedical research. Successful completion of this proposal will result in continued growth of both the user community and the feature set available through BioGPS.